Minimally invasive medical interventions are used increasingly today. For example for the treatment of coronary heart disease, surgical bypass operations on the heart are to a large extent giving way to balloon dilatation (PTCA=percutaneous transluminal coronary angioplasty) and the deployment of stents. Minimally invasive interventions are also being used increasingly in biopsies, spinal therapy and tumor ablations.
During the course of a minimally invasive intervention one or more medical instruments for example are inserted into the body of a patient for therapeutic or diagnostic purposes. Once a medical instrument has been inserted into the body of the patient it is no longer optically visible to a physician carrying out the intervention. To navigate the instrument in the body of the patient said instrument must therefore be visualized in image information in an appropriate manner for the physician. Different types of systems and methods are currently available for determining the position of the instrument in the body of the patient during minimally invasive medical interventions, as required for the visualization of the instrument, in particular the tip of the instrument, in image information from the inside of the body of the patient.
Progress in 3D x-ray imaging now allows 3D mapping of organs and also instruments in the body of a living being. However it is still difficult to distinguish between instruments, organs and bones in the x-ray image, while at the same time using as little x-ray radiation as possible for imaging and for determining the position of instruments.